Organize iCloud, Yahoo or Fastmail email automatically

What each provider does on its own

Checked on 30 September 2026 in each provider's help pages.

Rules are great for the predictable part: everything from your bank to Bank, everything from GitHub to Dev. They fall short for the rest, because they need you to know the sender or the words in advance, and new senders arrive every day. Fixed categories help, but "Updates" and "Promotions" don't tell a client's email from a colleague's.

Your own categories on any IMAP inbox

MailTag reads each new email once, on its own servers in the EU, and puts it into one of the categories you wrote: Clients, Invoices, Investors, Needs reply, whatever fits your work. It doesn't need to know the sender; it reads what the email is about. It works with iCloud, Yahoo, Fastmail, your own domain and any mailbox with IMAP.

Connect your mailbox

MailTag signs in with an app password, a separate code your provider generates for one app, never your main password:

• iCloud: at account.apple.com, Sign-In and Security → App-Specific Passwords, create one for MailTag. Your username is your iCloud address.
• Yahoo: in Account security, generate an app password.
• Fastmail: in Settings → Privacy & Security, create an app password with mail (IMAP) access.
• Anything else: use your provider's IMAP server (usually port 993, SSL) and an app password if you have two-step verification.

For Gmail, see How to create a Gmail app password.

Choose how categories show up

Outside Gmail there are no labels, so you choose one of three ways:

1. Move the less important mail into folders (recommended). Urgent and Needs reply stay in the inbox; newsletters, receipts, promotions and notifications move to their own folders (>Newsletter, >Receipt…). Your inbox keeps only what needs you.
2. Move everything into folders. Each email goes to its category's folder and the inbox stays empty.
3. Leave everything in the inbox with a mark. Nothing moves; each email gets a keyword with its category. Only some apps show keywords: Thunderbird and Fastmail do, Apple Mail doesn't.

Folders show up in every mail app, on your phone too, because they live in your mailbox, not in MailTag.

Then it runs by itself

MailTag checks for new email every 5 minutes. You can fix a label in one click (and it moves the email in your mailbox too), pin a sender or a whole domain to a category, and unsubscribe in bulk from the senders that fill your inbox. If you change your mind, Settings → Mailboxes → Remove labels takes all of MailTag's folders and marks back out, and your emails return to the inbox.

Rules and MailTag together

They don't compete. Keep your provider's rules for the fixed cases, and let MailTag sort everything the rules don't catch. If a rule moves an email out of the inbox first, MailTag never sees it (it only reads the inbox), so it stays where the rule put it.

FAQ

Does MailTag work with Outlook.com or Microsoft 365?

Not yet. It works with Gmail, iCloud, Yahoo, Fastmail and any mailbox with IMAP access.

Will my emails look different in Apple Mail or on my iPhone?

Only in where they are: sorted emails sit in folders like >Newsletter, which appear in the mailbox list like any other folder.

Is it safe to give MailTag an app password?

An app password only opens your mail, not your account settings, and you can revoke it any time at your provider. MailTag stores it encrypted, never stores your emails' content, and can't send or delete email.

How much does it cost?

The free plan sorts 100 emails a month. Paid plans start at $9 a month for up to 2,000 emails, and there's a 7-day free trial of Pro.